This invention relates to a focus control apparatus for automatically controlling the focus adjustment of an optical system in a television camera, etc.
Where an image is picked up through a television camera, etc., the focal depth or depth of field must be properly controlled at all times to obtain a clear-cut image. When in particular the image of an object in a relatively dark, near distance is picked up, since the depth of focus is shallow, the focus control must be made each time the distance between the object and the camera greatly varies. Unless, in this case, focus control is properly made according to the variation of the distance between the object and the camera, the resolution of a reproduced image is lowered, resulting in the image being out-of-focus. It is very difficult and cumbersome to effect focus control of the camera according to each variation of the object distance. A camera having manual focus control requires much skill on the part of the operator and involves a complicated arrangement for the enhancement of the focussing operation.